SHANGHAI (AFP) - Ten employees of a United States company that supplied foreign fast food outlets in China, including KFC and McDonald's, have been tried over a substandard meat scandal, a court official said on Thursday (Dec 31).

A court in Shanghai's Jiading district held a two-day trial earlier this week, said the official, who declined to be named.

Employees of Illinois-based OSI Group subsidiary Shanghai Husi Food are accused of mixing out-of-date meat with fresh product at a factory shut down by authorities in 2014.

The firm's customers in China previously included global fast food chains, among them McDonald's and KFC.

The court also tried employees of another OSI unit in the northern province of Hebei on the same charges of producing and selling inferior products, according to prosecutors.

The court named the accused but did not give their company positions. Media reports say they include both Shanghai Husi's general manager and the head of the factory in the city.

All the names appeared to be ethnically Chinese but it was not clear whether any might be foreign nationals.

The verdict will be given at a later date.

The controversy came to light after an investigative report by a Shanghai television station showed workers on the production line scooping meat off the floor and putting it back into processing machinery.

In a statement provided to AFP on Tuesday, OSI said it respected the country's legal process.

"We appreciate the opportunity to make our case in court. We continue to have full respect for China's legal system," it said.

China has seen a slew of scandals over food safety, but the case shook consumers as Western chain restaurants were widely viewed as upholding higher standards.